无硒氯化物体系电解金属锰消减氯气的实验研究

为了减少氯化物体系电解金属锰中氯气的溢出量,通过电化学测试及电解实验探究了阳极电流密度、锰离子以及氯化铵浓度对氯气溢出量的影响。阳极极化曲线测试表明,在氯化锰、氯化铵溶液中,阳极过程按电流密度分成两个区域:低电流区域,以Mn2+和Cl-的氧化为主要反应;高电流区域,以氧的析出反应为主要过程。电解实验证实上述结果,电流密度越高,氯气的溢出量越少;溶液中氯离子浓度越高,氯气的产生量也越多;纯氯化物体系电解金属锰在接近工业生产条件时,阳极过程难以完全抑制氯气的溢出,采用混合电解质为1 mol/L NH4Cl+0.5 mol/L(NH4)2SO4时,氯气溢出量低于检出限,无硒电解条件下,Mn沉积效率可达到72.81%。

An Experimental Study on Chlorine Reduction by Electrolytic Manganese in Selenium-Free Chloride System

In order to reduce the amount of chlorine gas spilled in the electrolytic manganese of the chloride system,the effects of anode current density,manganese ions,including the ammonium chloride concentration on the amount of chlorine gas spilled were investigated by electrochemical tests and electrolytic experiments.The anodic polarization curve test shows that,in the manganese chloride and ammonium chloride solutions,the anode process is divided into two regions,the oxidation of Mn2+and Cl-is the main reaction in the low current region.While in the high current region,the oxygen evolution reaction tends to dominate.Electrolysis experiments confirm the above results.The higher the current density is,the less the amount of chlorine gas spills out.The higher the concentration of chloride ions in the solution is,the more the amount of chlorine gas is generated.When the pure chloride system electrolytic manganese is close to industrial production conditions,it is difficult to completely suppress the overflow of chlorine gas.When the mixed electrolyte is 1 mol/L NH4Cl+0.5 mol/L(NH4)2SO4,the amount of chlorine gas leakage is lower than the detection limit.Under the condition of selenium-free electrolysis,the Mn deposition efficiency can reach 72.81%.